This invention relates to improved apparatus for tining bakery produced foodstuffs such as Kaiser or onion buns and related crusty rolls or loaves and, with minor modifications, English muffins.
The prior art has provided apparatus for the tining of foodstuffs, particularly English muffins, and the objective of such apparatus is to produce muffins which can be easily hand-opened at the time of consumption and which muffin has the flat rough surface characteristic that is best for grilling and toasting. A muffin which has been properly tined allows the ultimate user to easily open it thus exposing two rough surfaces on halves of equal thickness. Muffins split in this manner, for various reasons, look and taste far better after being toasted than muffins which have been cut with a knife.
In one form of prior art machine for tining muffins, a travelling conveyor is provided for delivering a series of muffins to a tining section to be tined and split. This tining section has first and second groups of tines operating from opposite sides of the conveyor belt with the tines being arranged to traverse the belt so that the tines are brought into interdigitating relationship with one another. As the tines move into interdigitating relation with one another they penetrate the muffins and at the moment of full penetration one set of tines is lifted out of the plane of interdigitation thereby to fractionally tear the muffin interiors. In this machine the length of the tine holder is equal to a predetermined number of muffin diameters. If, for example, the tine holders are ten muffin diameters in length, the conveyor will deliver ten muffins into the tining section. The tines penetrate the muffins, one set of tines is lifted relative to the other to effect the tearing action, following which the tines are withdrawn. The next ten muffins are then delivered to the appropriate spot and the same action is then repeated.
A disadvantage of the above machine is that it provides single stroke penetration of the muffins only and moreover the means for effecting lifting of one set of tines relative to the other to effect internal muffin tearing requires a fairly complex mechanical means as well as fairly complicated control systems all of which greatly increase the initial cost of the machine as well as increasing maintenance costs.
Other forms of muffin tining machines provide for continuous flow of the muffins on a conveyor in a straight line through the machine. The tine assemblies are disposed on opposite sides of the conveyors and the perforating tines are made to move with the muffins at the same speed as the conveyor. In order to accomplish this, the perforating tines are mounted on an endless chain-type arrangement with cam and lever arrangements being provided to impart the necessary lateral motion to the perforating tines. As might be expected, owing to the endless chain type arrangements on which the perforating tines are arranged, the structure is very complex mechanically and thus relatively costly to manufacture with the usual maintenance problems associated with complicated mechanical devices.
A further form of tining machine, which is a somewhat more refined version of the machine referred to immediately above, and which, preferably, receives muffins which have been tined once as by the aforementioned machine, is adapted to provide two-stroke penetration of each muffin from opposite sides. The tining mechanisms are so arranged that a small degree of auto-rotation of the muffin takes place between tining operations. This auto rotation is more or less random with the rotation taking place in one direction, or the other, or possibly not at all in certain cases when the forces on the muffin are essentially balanced. As with the preceding form of machine, the perforating tines are disposed on endless chain type arrangements to provide forward as well as lateral motion. This results in a very complicated mechanism having the cost and maintenance disadvantages referred to above.
Apparatus which overcomes many of the difficulties of the prior art machine, especially insofar as complexity and maintenance problems are concerned, is described in the co-pending Canadian application Ser. No. 435,791 filed Aug. 31, 1983 and commonly assigned herewith. This co-pending application describes a tining apparatus for muffins and related foodstuff which includes a support frame having a conveyor thereon defining an elongated path of travel along which items of foodstuff are conveyed in serially arranged relationship. This conveyor is moved at a selected rate of speed by a conveyor drive. First and second tine sets are mounted at opposite sides of the conveyor in opposing relationship to one another. Each tine set includes a plurality of tine disposed in spaced parallel relation to one another. Tine guide means are also provided for each of the first and second tine sets for guiding the tine in spaced parallel paths lying above the conveyor and fixed relative to the support frame. Each of the above-noted tine sets also has a length measured along the path of travel which is at least equal to a selected plurality of diameters or lengths of the foodstuff item. Tine drive means are provided for advancing and withdrawing the tines of the first and second sets so that the tines move toward and away from one another along their respective paths in timed relationship to the conveyor movement. This timed relationship is such that as each item of foodstuff is carried along the path of travel by the conveyor said tines of said sets enter into and withdraw from each foodstuff items a plurality of times of effect multiple piercing thereof.